Michael Coory

Cancer survival in Australia, Canada, Denmark, Norway, Sweden, and the UK, 1995–2007 (the International Cancer Benchmarking Partnership): an analysis of population-based cancer registry data

Summary Background Cancer survival is a key measure of the effectiveness of health-care systems. Persistent regional and international differences in survival represent many avoidable deaths. Differences in survival have prompted or guided cancer control strategies. This is the first study in a programme to investigate international survival disparities, with the aim of informing health policy to raise standards and reduce inequalities in survival. Methods Data from population-based cancer registries in 12 jurisdictions in six countries were provided for 2·4 million adults diagnosed with primary colorectal, lung, breast (women), or ovarian cancer during 1995–2007, with follow-up to Dec 31, 2007. Data quality control and analyses were done centrally with a common protocol, overseen by external experts. We estimated 1-year and 5-year relative survival, constructing 252 complete life tables to control for background mortality by age, sex, and calendar year. We report age-specific and age-standardised relative survival at 1 and 5 years, and 5-year survival conditional on survival to the first anniversary of diagnosis. We also examined incidence and mortality trends during 1985–2005. Findings Relative survival improved during 1995–2007 for all four cancers in all jurisdictions. Survival was persistently higher in Australia, Canada, and Sweden, intermediate in Norway, and lower in Denmark, England, Northern Ireland, and Wales, particularly in the first year after diagnosis and for patients aged 65 years and older. International differences narrowed at all ages for breast cancer, from about 9% to 5% at 1 year and from about 14% to 8% at 5 years, but less or not at all for the other cancers. For colorectal cancer, the international range narrowed only for patients aged 65 years and older, by 2–6% at 1 year and by 2–3% at 5 years. Interpretation Up-to-date survival trends show increases but persistent differences between countries. Trends in cancer incidence and mortality are broadly consistent with these trends in survival. Data quality and changes in classification are not likely explanations. The patterns are consistent with later diagnosis or differences in treatment, particularly in Denmark and the UK, and in patients aged 65 years and older. Funding Department of Health, England; and Cancer Research UK.

Cancer diagnosis, treatment, and survival in Indigenous and non-indigenous Australians: a matched cohort study

BACKGROUND Indigenous Australians do not have the high standard of health that Australians in general have, and have worse outcomes for several diseases such as cancer. However, few comparative data exist to prove this disparity. We assessed differences in disease stage at cancer diagnosis, treatment, and survival between these two populations in Queensland. METHODS Indigenous people diagnosed with cancer between 1997 and 2002 were identified through the cancer registry and compared with randomly selected non-Indigenous patients who were frequency-matched for age, sex, place of residence, cancer site, and year of diagnosis. We obtained details of treatment from hospital medical records. We restricted analyses to patients treated in the public sector, since less than 5% of Indigenous cases were treated privately. We used multivariate models, mainly Cox regression analyses, to assess differences. FINDINGS We studied 815 Indigenous and 810 non-Indigenous cancer patients. Stage at diagnosis differed significantly (p=0.007): 47% of Indigenous versus 53% of non-Indigenous patients had localised cancer, 22% versus 21% had distant metastases, and 12% versus 7% had no information on stage in the medical chart examined. Comorbidities such as diabetes mellitus or chronic renal disease were more common in Indigenous patients. These individuals were less likely to have had treatment for cancer (surgery, chemotherapy, radiotherapy), and waited longer for surgery (hazard ratio=0.84, 95% CI 0.72-0.97) than non-Indigenous patients. After adjustment for stage at diagnosis, treatment, and comorbidities, non-Indigenous patients had better survival than Indigenous ones (hazard ratio=1.3, 95% CI 1.1-1.5). INTERPRETATION Non-Indigenous cancer patients survive longer than Indigenous ones, even after adjustment for stage at diagnosis, cancer treatment, and greater comorbidity in Indigenous cases. We believe that better understanding of cultural differences in attitudes to cancer and its treatment could translate into meaningful public-health and clinical interventions to improve cancer survival in Indigenous Australians.

Stillbirths: recall to action in high-income countries

Variation in stillbirth rates across high-income countries and large equity gaps within high-income countries persist. If all high-income countries achieved stillbirth rates equal to the best performing countries, 19,439 late gestation (28 weeks or more) stillbirths could have been avoided in 2015. The proportion of unexplained stillbirths is high and can be addressed through improvements in data collection, investigation, and classification, and with a better understanding of causal pathways. Substandard care contributes to 20-30% of all stillbirths and the contribution is even higher for late gestation intrapartum stillbirths. National perinatal mortality audit programmes need to be implemented in all high-income countries. The need to reduce stigma and fatalism related to stillbirth and to improve bereavement care are also clear, persisting priorities for action. In high-income countries, a woman living under adverse socioeconomic circumstances has twice the risk of having a stillborn child when compared to her more advantaged counterparts. Programmes at community and country level need to improve health in disadvantaged families to address these inequities.

International trends in prostate-cancer mortality: the decrease is continuing and spreading.

AbstractObjective: To measure recent changes in prostate-cancer mortality across 24 developed countries. Methods: Mortality data for men aged 50–79 years were obtained from the World Health Organisation mortality database and we assessed trends in age-standardised mortality rates using joinpoint regression models. Results: Significant reductions in prostate-cancer mortality were observed in United Kingdom, United States, Austria, Canada, Italy, France, Germany, Australia and Spain, and downward trends were also observable in the Netherlands, Ireland and Sweden. Conclusions: Mortality declines for prostate cancer are now evident in 12 out of the 24 developed countries considered in this analysis. Increases in PSA screening and better treatment of early-stage disease, possibly acting in combination, remain plausible hypotheses.

Systematic review of multidisciplinary teams in the management of lung cancer.

BACKGROUND In several countries, clinical practice guidelines for lung cancer recommend that multidisciplinary (MD) teams should be used to plan the management of all lung cancer patients. We conducted a systematic review to evaluate and critically appraise the effectiveness of multidisciplinary teams for lung cancer. MATERIALS AND METHODS Medline searches were carried out for the period 1984 to July 2007. We included any study that mentioned team working among specialists with diagnostic and curative therapeutic intent, where members of the team met at a specified time, either in person or by video or teleconferencing, to discuss the diagnosis and management of patients with suspected lung cancer. All study designs were included. We were particularly interested in whether multidisciplinary working improved survival but also considered other outcomes such as practice patterns and waiting times. RESULTS Sixteen studies met the criteria for inclusion. Statistical pooling was not possible due to clinical heterogeneity. Only two of the primary studies reported an improvement in survival. Both were before-and-after designs, providing weak evidence of a causal association. Evidence of the effect of MD teams was stronger for changing patient management than for affecting survival. Six of the studies reported an increase in the percentage of patients undergoing surgical resection or an increase in the percentage of patients undergoing chemotherapy or radiotherapy with curative intent. CONCLUSION This systematic review shows limited evidence linking MD teams with improved lung cancer survival. This does not mean that MD teams do not improve survival, merely that currently available evidence of this is limited. It seems intuitively obvious that MD teams should improve outcomes for lung cancer patients, but there are difficulties in conducting randomised trials to show this. The best way forward would be prospective evaluation of the effectiveness of MD teams as they are implemented, paying particular attention to collecting data on potential confounders.

Population-Based 20-Year Survival Among People Diagnosed With Thin Melanomas in Queensland, Australia

PURPOSE The 20-year survival rates are unknown for the majority of melanoma patients-those with thin melanomas. We determined 20-year survival rates of patients diagnosed with thin melanomas (≤ 1.00 mm) in the general population and also determined the main prognostic factors. PATIENTS AND METHODS Available clinical and histologic data from the Queensland Cancer Registry were obtained for all patients diagnosed with a single thin invasive melanoma from 1982 to 2006 and matched against national death registration data. Melanoma-specific survival estimates to December 31, 2007, were assessed, and subgroup differences in prognosis were determined by fitting multivariate Cox proportional hazard models. RESULTS Among 26,736 people in the state of Queensland diagnosed with thin melanomas, the 20-year survival was 96%. The most influential determinants of prognosis were tumor thickness ≥ 0.75 mm (adjusted hazard ratio [HR], 4.33; 95% CI, 2.8 to 6.8 compared with tumors < 0.25 mm) and patient age at diagnosis older than 65 years (HR, 2.8; 95% CI, 1.8 to 4.5) compared with age younger than 25 years. Acral lentiginous and nodular tumors, male sex, tumor site on the scalp or neck, or tumor invasion of the entire papillary dermis each independently increased the risk of dying from thin invasive melanoma. CONCLUSION The outlook for patients with thin invasive melanoma is positive, although continued clinical vigilance is warranted for patients with nodular melanoma and those with the thickest tumors.

Comment on: heterogeneity in meta-analysis should be expected and appropriately quantified

Higgins in his commentary on the study by Patsopoulos and coworkers outlines some of the limitations of I in assessing heterogeneity in a metaanalysis. These limitations have perhaps not been as explicitly explained before. They have particular implications for assessing heterogeneity in meta-analyses of cohort and database studies and this aspect is worthy of further comment. As pointed out by Higgins, I is not a point estimate of the between-study heterogeneity. It is the proportion of total variation in the point estimates that is attributable to between-study heterogeneity. The total variation is comprised of between-study variation and within-study variation. If the individual studies have large sample size, such that the within-study variation is small, then I could be large (say475%), even if the between-study variation is small. This is particularly a problem for meta-analyses of cohort and database studies, which typically have large sample sizes. The advantages I are that it does not depend on the number of studies in the meta-analysis or the effect measure used (e.g. odds ratio, risk ratio, hazard ratio, mean). However, it does depend on the size (precision) of the individual studies. It might be sensible to compare I across different meta-analyses, where the component randomised controlled trials (RCTs) all have about the same sample size. However, it is not sensible to compare I across meta-analyses of RCTs (sample size in the 100s) and meta-analyses of cohort or database studies (sample size in the 1000s). An alternative is to report the between-study variance ( ), calculated as part of a random-effects meta-analysis. The disadvantage of 2 is that it depends on the effect measure (e.g. odds ratio, risk ratio, hazard ratio); that is, it does not provide a standardized way of measuring heterogeneity. Meta-analyses of large observational studies (that address policy questions) are increasingly being used to support funding decisions. Statisticians should strive to display and communicate the results in a way that is useful to decision makers. In this context, little would be lost if quantitative measures of statistical heterogeneity (e.g. Q and its P-value, I, ) were not reported. As Higgins points out, any amount of heterogeneity is acceptable, provided pre-defined inclusion criteria are met. A more useful approach would be to focus attention on the forest plot. If one or more studies are outliers, then there is more uncertainty about the mean measure of effect across all studies. This uncertainty is not necessarily adequately depicted by the confidence interval from a random effects meta-analysis, so that judgement is needed when applying results (as in all areas of applied statistics). Increasingly complex analyses, which are mysterious and difficult for nonstatisticians to understand, do not necessarily shed light on the problem at hand.

A systematic review of two outcomes in autism spectrum disorder - epilepsy and mortality

Aim  It has been reported that rates of epilepsy and mortality are higher among the population with autism spectrum disorder (ASD) than in the general population. The aim of this systematic review is to provide comprehensive evidence for clinicians, carers, and people with ASD regarding these outcomes.

Using routine inpatient data to identify patients at risk of hospital readmission

BackgroundA relatively small percentage of patients with chronic medical conditions account for a much larger percentage of inpatient costs. There is some evidence that case-management can improve health and quality-of-life and reduce the number of times these patients are readmitted. To assess whether a statistical algorithm, based on routine inpatient data, can be used to identify patients at risk of readmission and who would therefore benefit from case-management.MethodsQueensland database study of public-hospital patients, who had at least one emergency admission for a chronic medical condition (e.g., congestive heart failure, chronic obstructive pulmonary disease, diabetes or dementia) during 2005/2006. Multivariate logistic regression was used to develop an algorithm to predict readmission within 12 months. The performance of the algorithm was tested against recorded readmissions using sensitivity, specificity, and Likelihood Ratios (positive and negative).ResultsSeveral factors were identified that predicted readmission (i.e., age, co-morbidities, economic disadvantage, number of previous admissions). The discriminatory power of the model was modest as determined by area under the receiver operating characteristic (ROC) curve (c = 0.65). At a risk score threshold of 50, the algorithm identified only 44.7% (95% CI: 42.5%, 46.9%) of patients admitted with a reference condition who had an admission in the next 12 months; 37.5% (95% CI: 35.0%, 40.0%) of patients were flagged incorrectly (they did not have a subsequent admission).ConclusionA statistical algorithm based on Queensland hospital inpatient data, performed only moderately in identifying patients at risk of readmission. The main problem is that there are too many false negatives, which means that many patients who might benefit would not be offered case-management.

Cancer survival for Aboriginal and Torres Strait Islander Australians: a national study of survival rates and excess mortality

BackgroundNational cancer survival statistics are available for the total Australian population but not Indigenous Australians, although their cancer mortality rates are known to be higher than those of other Australians. We aimed to validate analysis methods and report cancer survival rates for Indigenous Australians as the basis for regular national reporting.MethodsWe used national cancer registrations data to calculate all-cancer and site-specific relative survival for Indigenous Australians (compared with non-Indigenous Australians) diagnosed in 2001-2005. Because of limited availability of Indigenous life tables, we validated and used cause-specific survival (rather than relative survival) for proportional hazards regression to analyze time trends and regional variation in all-cancer survival between 1991 and 2005.ResultsSurvival was lower for Indigenous than non-Indigenous Australians for all cancers combined and for many cancer sites. The excess mortality of Indigenous people with cancer was restricted to the first three years after diagnosis, and greatest in the first year. Survival was lower for rural and remote than urban residents; this disparity was much greater for Indigenous people. Survival improved between 1991 and 2005 for non-Indigenous people (mortality decreased by 28%), but to a much lesser extent for Indigenous people (11%) and only for those in remote areas; cancer survival did not improve for urban Indigenous residents.ConclusionsCancer survival is lower for Indigenous than other Australians, for all cancers combined and many individual cancer sites, although more accurate recording of Indigenous status by cancer registers is required before the extent of this disadvantage can be known with certainty. Cancer care for Indigenous Australians needs to be considerably improved; cancer diagnosis, treatment, and support services need to be redesigned specifically to be accessible and acceptable to Indigenous people.